学习基础开发技能_Android

20240207,

1.日志

Log.d("ning", "onCreate");

2.win11开启android虚拟化支持

勾选这俩:参考 https://zhuanlan.zhihu.com/p/658580570

3.运行app指的是运行某个模块,而非运行某个项目

4.app工程分为两个层次,一个是项目,一个是模块。

5.模块依附于项目,一个项目至少有一个模块,一个项目可以有多个模块。

6.我们所说的“编译运行app”,指的是运行某个模块,而不是整个项目,因为模块才对应于实际app。

20240209,

1.android studio里Ctrl+shift+o自动组织导入

2.activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">
    <TextView android:id="@+id/tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="hello world!"/>
</LinearLayout>

3.MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView tv = findViewById(R.id.tv);
        tv.setText("你好,世界!");
    }
}

20240210,

1.activity_main2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Activity main 2 by manual creation"/>
</LinearLayout>

2.activity_main3.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="activity main 3 by create empty activity"/>
</LinearLayout>

3.activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">
    <TextView android:id="@+id/tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="hello world!"/>
    <Button
        android:id="@+id/buttonManual"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="跳转(通过手动创建的)MainActivity2"/>
    <Button
        android:id="@+id/buttonMenu"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="跳转(通过empty activity菜单创建的)MainActivity3"/>
</LinearLayout>

4.MainActivity2.java

public class MainActivity2 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
    }
}

5.MainActivity3.java

public class MainActivity3 extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
    }
}

6.AndroidManifest.xml

<activity
            android:name=".MainActivity3"/>
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".MainActivity2" />

7.MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView tv = findViewById(R.id.tv);
        tv.setText("你好,世界!");

        Button buttonManual = findViewById(R.id.buttonManual);
        buttonManual.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent();
                intent.setClass(MainActivity.this, MainActivity2.class);
                startActivity(intent);
            }
        });

        Button buttonMemu = findViewById(R.id.buttonMenu);
        buttonMemu.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent();
                intent.setClass(MainActivity.this, MainActivity3.class);
                startActivity(intent);
            }
        });
    }
}

8,

posted on 2024-02-07 07:54  平凡力量  阅读(6)  评论(0编辑  收藏  举报